中文摘要：

自然条件下,采用湛水107-13营养液为基础配方,在经消毒处理的天然海水中添加不同氮、磷质量浓度的营养盐进行亚心形扁藻的培养。结果表明,当氮、磷质量比为17时,最适合亚心形扁藻的生长。不同磷质量浓度梯度对亚心形扁藻的生长和生长率K具有显著性的影响（P〈0.05）。当磷质量浓度为8 mg/L时,其相对生长常数和生长率K值均高于其他质量浓度处理。不同氮质量浓度梯度对亚心形扁藻生长具有显著性影响（P〈0.05）,但对亚心形扁藻生长率K的影响不显著（P〉0.05）。高质量浓度氮对亚心形扁藻的生长影响作用最大（P〈0.05）。在培养过程中,高质量浓度氮、磷培养液中NO3--N和PO43--P的下降速率高于低质量浓度中NO3--N和PO43--P浓度的变化,并呈现出显著性的差异（P〈0.05）。表明在高质量浓度营养盐条件下培养亚心形扁藻,会导致营养盐相对利用率的下降。

英文摘要：

Alga Platymonas subcordiformis was cultivated in Zhanshui 107-13 nutrient medium containing different concentrations of nitrogen and phosphorus.The relationship between the alga growth and the dynamic of NO-3-N and PO3-4-P concentrations were investigated at a natural condition.The optimum N/P ratio for the alga growth was found to be 17.There were higher relative growth index and the growth rate in the alga cultivated at phosphorus rate of 8 mg/L than those at the other concentrations（P0.05）.The alga had significant difference in growth at different nitrogen concentrations（P0.05）,but no significant difference in the growth rate（P0.05）.The dynamics of NO-3-N and PO3-4-P levels showed significant difference in different concentrations of nitrogen and phosphorus.There was more rapid decrease in N,and P concentrations at higher concentrations than that at lower concentrations,indicating that the alga needs more nutrients for increase in unit biomass under higher nutrient concentration.